docs: add UX/UI committee report with gap analysis

11-expert committee review of CodeFrame UX/UI identifying:
- Steps 1-7 at B+ grade (functional)
- Steps 8-10 at F grade (Git/PR workflow missing)
- Created 11 new GitHub issues (#270-#280)
- Re-labeled 8 over-engineered issues as Future
- Closed 2 superseded issues (#116, #117)

Key findings:
- P0: Implement Git branch/commit APIs and UI
- P0: Implement GitHub PR creation/merge workflow
- P1: Add global progress stepper and onboarding
- P2: Refactor LeadAgent, Dashboard, DiscoveryProgress

Author: Test User